|
|
MOVEABLE
PULLEY
|
|||
| In a moveable pulley, one end of the rope which passes around the pulley is tied to a firm support ‘O’ and effort ‘P’ is applied to the other end. The load is hung from the hook of the block. As the load is applied by two segments of rope, | |||
| the effort becomes twice of the applied value i.e. | |||
 |
|||
|
EFFORT
= 2 x P
|
|||
| In equilibrium condition we have | |||
|
Load
= Effort
W = 2P |
|||
|
Dividing
both sides by P
|
|||
|
W/P
= 2
|
|||
|
but
[W/P = M.A]
|
|||
| thus | |||
|
M.A.
= 2
|
|||
| This shows that a moveable pulley can lift a load double the effort. | |||
|
INCLINED
PLANE
|
|||
| Any
smooth plane surface which makes an angle q
with the horizontal surface
is called an “Inclined plane”. Where 0o < q <90o or values of q lies between 0o and 90o . |
|||
 |
|||
|
USES
OF
INCLINED PLANE |
|||
| For latest information , free computer courses and high impact notes visit : www.citycollegiate.com | |||
| It is a simple machine and is used to raise heavy loads by applying little effort. | |||
|
MECHANICAL
ADVANTAGE
OF INCLINED PLANE |
|||
| In the figure AB is an inclined plane which makes an angle q with the horizontal plane. A load ‘W’ is being raised from A to B by applying an effort ‘P’. If we neglect the force of friction between load and inclined plane | |||
|
Output
= input
Weight x height = effort x distance W x h = P x L W*h/P = L W/P = L/h OR W/P = 1/h/L in right angled DOAB Sin q = OB/AB Sin q = h/L [ perpendicular/hypotenuse = sinq] therefore W/P = 1/sinq but [W/P = M.A.] Thus M.A. = 1/sinq |
 |
||
| This expression shows that mechanical advantage of an inclined plane depends upon the value of sinq. | |||
| For latest information , free computer courses and high impact notes visit : www.citycollegiate.com | |||